Field of Invention
The present invention relates generally to data communication networks and devices, and relates more particularly to .1BR network environments.
Description of the Related Art
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
As information handling systems provide increasingly more central and critical operations in modern society, it is important that the networks are reliable. One method used to improve reliability is to provide redundant links between network devices. By employing redundant links, network traffic between two network devices that would normally be interrupted can be re-routed to the back-up link in the event that the primary link fails.
In a network switch, there are a limited number of ports and each switch is managed individually. This complicates the management of switches within the network. One way to decrease the complexity in management of switches and increase the number of ports is to use port extenders. Port extension provides the capability to group different switches into a single logical switch, thus making it easier to manage different switches and also increases the number of ports which can be managed. In a port extender environment, a single controlling point is needed to manage the different switches and these managed switches are called the port extenders.
In some prior art solutions, a controlling bridge (CB) is used as the controlling point in a .1BR network. In prior art solutions, the controlling bridge statically selects the path through the port extenders.
In .1BR enabled virtual machine (VM) switched networks, load balancing of non-unicast/destination lookup fail (DLF) traffic either in the fabric or for the virtual port-link aggregation group (VP-LAG) cannot be handled by the controlling bridge itself. The prior art solutions choose a link aggregation group (LAG) member for a VP-LAG upfront in the control plane of the controlling bridge and hence it only achieves static load balancing.
In a multi-level port extender (PE) environment, the path to reach the port extender from the controlling bridge is also statically chosen in the control plane for non-unicast traffic. Hence it is subjected to only static load balancing.
FIG. 1 shows an example of a prior art solution. FIG. 1 shows controlling bridge 110, four port extenders 120, 130, 140, and 150, two hosts 160 and 170. The hosts 160 and 170 are the receivers of the information. The fabric links between controlling bridge and port extenders can be enabled with .1BR. The controlling bridge discovers all the port extenders through IEEE 802.1BR standard mechanism.
For unicast traffic, paths to reach port extender 3 140 and port extender 4 are considered as equal cost multi path (ECMP) paths and hence the controlling bridge 110 can dynamically load balance the traffic via port extender 1 120 or port extender 2 130. However, for non-unicast or destination lookup fail traffic, the controlling bridge load balancing is only static.
There are different paths, for example, to reach host 1 160 a path is through PE1 120 and PE3 140 or PE1 120 and PE4 150. There is also a path through PE2 130 and PE3 140 or PE2 130 and PE4 150. There are four possible paths. The prior art selects a path statically and programs the path to the port extenders 120, 130, 140, and 150.
For non-unicast traffic LAG hashing, the packet fields are used to compute a hashing scheme and the same is passed as a metadata in the packet to all other units via stack links. For a given hash index, only 1 port is opened up for the LAG, whereas for the same hash index, in other stack units all the local ports for that LAG is blocked. Thus, the LAG hashing occurs for non-unicast traffic.
One disadvantage of this system is that static load balancing of VP-LAG members, as well as path to reach a given multi-level port extender, leads to inefficient load balancing.
Another disadvantage of this system is that static load balancing of VP-LAG members, as well as path to reach a given multi-level port extender, leads to oversubscription of channel members.
Accordingly, what is needed are systems and methods that can achieve dynamic load balancing of non-unicast traffic.